Designing circuits to meet stringent performance specifications over a wide range of operating conditions generally requires using precision references. By coupling circuit operation to a highly stable, precision reference, the influence of even large variations in supply voltage, temperature, and processing parameters on circuit performance can be minimized or even entirely eliminated. Familiar examples of precision references are crystal oscillators, bandgap voltage references, and precision external resistors.
Referenced-based circuits often are analog in nature and suffer from sensitivity to voltage supply noise. Designing such referenced-based circuits to operate in the presence of voltage supply noise can be very challenging. If a circuit could be designed to meet stringent performance specifications without relying on precision references, circuit design in many cases would become simpler.
It is therefore desirable to provide an alternative approach to relying on precision references to compensate a circuit for actual operating conditions, i.e., supply voltage, temperature, and processing parameters. The present invention addresses this issue.